In this paper, the coloring mechanism of purple jadeite was investigated by X-ray diffraction, X-ray fluorescent spectrum and other methods. The content of Fe was high in the purple jadeite, while that of Mn was rather low. At the oxidation atmosphere, the color of purple jadeite was thinned out at 650 ℃, which attributed to the oxidation of Fe2+ to Fe3+. There was no absorption peak at 540 nm (the characteristic peak of Mn3+) in the ultraviolet-visible absorption spectrum before and after heat treatment of the purple jadeite, which means that the manganese ion wasn't the main factor for coloring. At the reducing atmosphere, the color of the purple jadeite was deepened and darkened via heat treatment due to the increase of the Fe2+content, the enhanced transition from Fe2+ to Fe3+, and thus absorption band covering all visible light area. The transition between Fe2+ and Fe3+ was the main reason for coloring of purple jadeite.